Question:
A constant current flows in a horizontal wire in the plane of the paper from east to west as shown in figure. The direction of magnetic field at a point will be north to south.
(a) directly below the wire
(b) directly above the wire
(c) at a point located in the plane of the paper, on the north side of the wire
(d) at a point located in the plane of the paper, on the south side of the wire.
Solution:
(d).
Explanation : Applying right hand thumb rule to know the direction of the magnetic field.